1. Field of the Invention
The present invention relates to a food debris filtering apparatus for a dishwasher and a method thereof, and particularly to an improved food debris filtering apparatus for a dishwasher and a method thereof capable of more effectively discharging food debris by separating the same from washing water and resupplying the filtered washing water so as to wash dishes, so that dishes washing  a dishwashing efficiency is increased.
2. Description of the Conventional Art
FIG. 1 shows a conventional dishwasher, which includes a washing chamber 2 formed inside a body 1, and a door 3 attached to the front portion of the body 1.
A dish rack 4, on which dishes (not shown) are placed, is disposed at the inner upper portion of the washing chamber 2, and a spray arm 5 having a plurality of washing water spray openings 5a formed on the upper surface of the same is disposed at the central portion of the washing chamber 2, and a heater 6 is disposed at the bottom of the washing chamber 2.
Washing water is sprayed toward dishes from the washing water spray openings 5a in a state that  when the dishes are placed on the dish rack 4 of the washing chamber 2, thus washing the dishes. Here, the heater 6 is directed to heating the interior of the washing chamber 2 so that dishes can be easily washed.
Meanwhile, the conventional dishwasher further includes a filtering apparatus F for filtering washing water, which is polluted through a dish washing operation, a washing water circulation unit such as a washing pump for supplying the washing water filtered by the filtering apparatus F to the spray arm 5, and a washing water discharging unit such as a discharging pump for discharging part of the washing water from the filtering apparatus F to the outside of the system  dishwasher.
As shown in FIG. 2, a washing water (containing food debris) gathering tub 7 having a predetermined depth is disposed below the washing chamber 2, and first, second, and third filters 8, 9, and 10 of the filter apparatus F are disposed at the washing water gathering tub 7. A circulation tube 11 is connected between a predetermined portion of the side wall of the washing water gathering tub 7 and the spray arm 5. A washing water discharging tube 12 is connected to the bottom of the washing water gathering tub 7, and a washing water circulation unit P1 such as a filtering unit and a washing water discharging unit P2 such as a discharging pump which  are disposed at the circulation tube 11 and the discharging tube 12, respectively.
The first filter 8 is formed with a net having a plurality of net eyes having a certain size capable of filtering relatively big size  large food particles, and the second filter 9 is formed with a net having a plurality of net eyes having a certain size capable of filtering intermediate size food particles, and the third filter 10 is formed with a net having a plurality of net eyes having a certain size capable of filtering small food particles.
The second filter 9 is engaged to the washing water gathering tub 7, and  the first filter 8 is engaged to the intermediate portion of the second filter 9, and the third filter 10 surrounds the first filter 8 and is connected to the discharging tube 12.
The conventional dishwasher including the filtering apparatus F, the washing water circulation unit P1, and the washing water discharging unit P2 is directed to filtering washing water by permitting the washing water to flow through the first, second, and third filters 8, 9, and 10 through the bottom of the washing chamber 2. The filtered washing water is supplied to the spray arm 5 in cooperation with the washing water circulation unit P1, and the washing water is sprayed from the washing water spraying openings 5a of the spray arm 5, so that a dish washing operation is performed through the above-mentioned procedures.
Meanwhile, food particles clogged at the net eyes of the third filter 10 are discharged to the outside of the system  dishwasher through the discharging tube 12 in cooperation with the washing water discharging unit P2.
However, the conventional dishwasher has disadvantages in that relatively small food particles are not effectively filtered by the filtering apparatus F, and the recirculated washing water is not clean enough to wash dishes. In addition, washing water should be resupplied from the outside of the system  dishwasher, so as to reduce the pollution level of the washing water. moreover  Moreover, a lot of washing water is required for a long time, so that a washing efficiency is decreased.